Some conventional electric power conversion devices use complex windings for a transformer, to obtain a multioutput power supply configuration (for example, see Patent Document 1 below). That is, an object of the conventional-art electric power conversion device is to, in charging two DC power supplies with power from an AC power supply using a transformer having complex windings magnetically coupled with each other, set a priority on one of the DC power supplies to be charged. In the case where there is no AC power supply, one of the DC power supplies is used as a supply source to charge the other DC power supply by using a bidirectional switch.